Shock relief unit for crutches



Aug. 9, 1949.

M. SHELLHOUSE ETAL SHOCK RELIEF .UNIT FOR CRUTCHES Filed 001;. 15, 1946 E w O H .0 a 4 2 H M .l l. u ..III| u m a L a 0 4 6 E 6 M 6 v I :3 4 o. 5 l f 7 a I 4 c w 3 3 n yd 2 I I III 4 M y um 7 n n V M M 5 m 4 m I 0 l I l 421' a 6 o .1 T! l 3 I W m 3 Patented Aug. 9, 1949 OFFICE SHOCK RELIEF UNIT FOR CRUTCHES Michael Shellhouse and Cecil E. Cleaver,

Gary, Ind.

Application October 15, 1946, Serial No. 703,388

Claims.

This invention relates to improvements in crutches.

In the usual or ordinary type of crutch there is found, secured between the lower ends of the side pieces forming the crutch frame, a solid post of Wood which carries a rubber or rubber and fabric tip upon its lower end. In using a crutch of this character the user is continually subjected to jars due to the insufficient resiliency of the rubber tip which is provided more for the purpose of preventing the crutch from slipping than for relieving the user of jars.

The present invention has for its primary object to provide an improved crutch foot portion of a yieldable character designed to absorb shock incident to the use of the crutch and thereby make its use more comfortable.

A further and more specific object of the invention is to provide a foot piece or unit for a crutch, including a fixed cylinder and a movable piston in the cylinder, upon the lower end of which piston a friction tip is mounted. Within the cylinder a yieldable unit in the form of a coil spring normally urges movement of the piston outwardly and the inward movement of the piston in the cylinder is yieldingly resisted both by the coil spring and by compressed air which is permitted to escape slowly through a control valve. Accordingly the device of the present invention provides a foot piece by which there is obtained an air cushion which makes possible the use of the crutch without subjecting the user to shocks and jars as in the ordinary type of crutch structure.

Another object of the invention is to provide an air cushion shock relief unit or foot piece for a crutch which is of relatively simple construction and which may be readily substituted for the present solid post foot piece.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming a part of the specification with the understanding, however, that the invention is not confined to a strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawing:

Figure 1 is a view in elevation of a unit constructed in accordance with the present invention, showing the same mounted between the lower ends of the side portions of a crutch frame, the lower part of the unit piston being broken away. 7 I v Figure 2 is a longitudinal section taken substantially on the line 2-2 of Figure 1.

Figure 3 is an enlarged detail showing the air admission and exhaust valves.

Figure 4 is a transverse section taken substantially on the line 4-4 of Figure 1.

Referring now more particularly to the drawing there are shown in Figure 1 the lower ends of the two side portions of a crutch frame, such ends of the frame being designated l0.

In accordance with the present invention there is provided a relatively long cylinder l l of an outside diameter to fit snugly between the crutch frame portions Ill, in the manner illustrated. The lower end of this cylinder 1 I has the wall thickened slightly as indicated at I2, throughout a portion of the length of the cylinder, thereby providing the flange or shoulder I3 upon which rests a flat Washer or collar M. The lower ends of the frame portions I 0 rest upon this collar l4 and the opposite sides of the collar lying in'a line perpendicular to the plane in which theportions Ill lie, are turned upwardly against the adjacent sides of the cylinder I I as indicated at M Directly above the collar M a bolt l5 passes diametrically through the cylinder and the head It at one end of the bolt and the nut I1 threaded upon the other end, lie in suitable recesses i8 formed in the lower ends of the frame portions l 0 as shown in Figures 1 and 4.

The bolt l5 maintains in position and limits the inward and outward movements of the tubular piston l9 which extends into the open end of the cylinder and has snug contact with the inner wall thereof as shown in Figure 2. This function of the bolt I5 is performed by providing the upper end of the piston 19, at opposite sides, with the longitudinal guide slots 29 through which the bolt I5 passes.

The lower end of the piston I9 is closed as indicated at 2| and is designed to have fixed thereon an anti-skid tip 22 of the type commonly employed upon crutches.

The inner and upper end of the piston I9 is closed by the plug 23 and this has secured to the top surface thereof, by means of the capscrew 24 and the plate or disk 25, the cup washer 26 which bears against the inner wall surface of the cylinder I l to prevent the escape of air from the cylinder around theend of the piston, as the piston is driven inwardly,

The top end of the'cylinder l I is closed by the valve head 21. This head 21 has the central or axial bore 28 formed therethrough, the inner end portion of which boreis suitably constricted to form a ball valve seat 29 upon which rests v the ball check valve 30. The outer end portion of the bore 28 is of slightly enlarged diameter and is screw threaded as indicated at3l to receive the socket nut 32, through the center of which isformed a relatively small diameter "air escape passage 33. Within the inner end of the bore 28 3 there is interposed between the ball check 35 and the nut 32, the spring 34 which constantly yieldingly presses the ball onto the seat 29 to close the inner end of ithe here and thereby ,preveut the entrance of air into the cylinder "upon the outward movement of the piston I9.

Within the cylinder I I is a coil spring 35 which bears at its upper end against lthe ill-16161 side "of the head 27 and at its lower end against the disk 25. This spring 35 constantly urges thepiston I9 outwardly to the limit of its movement as controlled by the bolt I5.

Fixed to the top of the valve head 21 is the substantially U-shaped clevis 36. Thisrolevis has the upstanding side portions 31 and the intermeiiiateconneoti-ngmorltion =38 which lies ;upon-'the top of the valve head .212fl1'1d which iszpltovided witlrsan opening 13.9 through which the socketmut 32 may be introduced into .orwithdra-wn ifIlOl'Il of the cylinder, an outwardly opening air exhaust port in said head, a substantially U-shaped clevis secured to the head and adapted to secure the end lofitheacylinder between adjacent side :portions of "the crutch-frame, a piston'slidablein the cylinder and extending from the other end thereof, resili- -ent means normally urging the piston outwardly, means tcarriedjby the cylinder and having loose connection with the piston for limiting the inward and outward movement of the piston, a ground engaging tip at the outer end of the piston,andayalveoontrolled air intake ort for the cylinder.

'3. In a crutch structure having a frame terminating in spaced lower end portions, a cylinder .psitione.d between zandsecured to said end .por-

tions of the frame, means carried by the-cylinder iagainst 'which :the. end portions bear, a piston within i'the cylinder and extending downwardly position. The .side "portions :31 position against :therefrom, aground-engagingtipat theouter end ;the inner sidesofthemcrtions Ml-10f the :orutoh Eframeeand are ;;prov.ided with suitable apertures 40 to receive ithewseouring :bolts AI which pass .thr.ough2the crutch dirame side portions lasushown :imFigure 11. .Thus :the upper end-of the-.eylinder iH u's afilrmly seem' ed zin place --and thellower lends i0f*th portions --L0.of ithe frame .rest {upon the ,collar :14 which tin turnz-nests upon=the-shoulder 1| 3 (of :the cylinder uthereby i-providing a :firm and mafasuppontl for the :frame :on :the --ioot assembly. :Ad-jacent to the [upper end of the :eylinder .I. I :there is {provided 58 11 lair ."intake port :42 and (this as wavered byla vallve unit twhiohis generally designated firand which. comprisesa :hollow Sh8l1'144 having anair inletopening-adfi, and -a,-suitable air control :valyezassemblydfi :positioned in theshell. This-assembly :consists 0f ia :seat plate 4a :having :ianropening-b over which lies the valve disk 0. .eAaoapzd covers -.the--inner. side 10f ithe plate :wand aha-s the lair openings --:e. The disk 40 epresaedtoitmseatmventhe opening-,b by the spring eBytthismea-nsair passes-into the eylinderby way of the openingsfii sand dfi and ;e upon outmovementiaof .the piston. whileyanywsuitab1e;'type of halve sassernbly may be used-in ethe rshell-dilgpreferenoe had .for a valve of the -.-f orm llSBd fuel j: pumps v01 :a -well known make: and 'which :arerof' the construction "here shownsend described.

from the ioregoing itvwill bereadil-yr lpparent rthat rthere is 1 provided .in the present -:invention a novel crutch foot unit ==which provides ravyieldsable :lcushionazsupport 5 for the crutch to give zthe degree .of com fiort tin :connectionwith 11353186 We claim: it. The combination. withraacrutch :having a ef rame ;,-pnovlided with sspaoed parallel lower ,end portions, of ill-10118111011 foot :unit momprising'a :oylinder interposed .betweemsaid end; portions, :3- :substantially U-shaped clevis secured to; an .end 1101: the cylinder and having, spaced ;.sid e mortious secured to theadjaeent portions of the frame, :a collar encircling the cylinder :and having rthe flower; endseilth'e; fromemortions:restingxthereon,

so, piston 'sl-idablerln aishe. cylinder and-having rem "end extending ,downwardly therefrom, .-a aground zengaging tipat the, outer zendsofithepiston ,:.means withinthercylindercnormalla urgingmovementzof the ,jJiStOIl outwardly, valve controlled air. inlet -and=outletportsrfor.thecylinder, andzmeansilim- -i tingythe ontwarmmovement- :of the piston.

l2. :Avcnutoh foot runit designed -,to be :secured ubetween mhe lower end portionsoi a crutch frame, summarising "a cylinder. ,ea malve head in ione end pfthepiston, a washer carried at the inner end .Oflthe piston and slidably engaging the inner wall ofvthe cylindenspring means within thecylinder :normally urging 'movement rOf the ,piston out- 'wardly, --.v.alv.e controlled air inlet and exhaust ports ;f.or1.the cylinder, ,a substantially :U -shaped clevis secured to the innernend of :the cylinderrand having spaced side vmembers positioned against "the inner sides of the .said Jframeportions, and means :securingthe said sides of the 'clevisto the gadiacenttnortions of :the frame.

4. In a crutch structure having a rframeter- :minating in -spaced lower endportions, :a.;Qylinder :having a substantial part, of i its dength-positionod sbetween .said end ;portions ;of the frame, means .=eonneoting =the cylinder with said-:endportions, said cylinder at its lower lend being formed :to provide anwencircling; shoulder, a hat :collar -encirclinglthe cylinder above and resting-uponxsaid 40\shoulder, the ends :ofsaid lower end portions restmg upon :said collar, the collar at opposite :sides being turned :up -towbearaagainst adjacent ;portions of the cylinder between wthesaid end l-portions .of the crutch frame, a piston slidably :engaging in athfi cylinder and extending downwardly belowwthe lower end -athere.of, "a *tip upon -the lower end "of .the :piston .for engaging the ground, resilient means-within the cylinder nor-- mally urging movement of the pistonroutwardly,

' an-airdnlet waive {for the uppenend .of the cylin- 'der, an air outlet bleed valvecin the .upper end .of i-the cylinder, and means limiting-the outward movement ;ofthe :piston, in .the cylinder.

5. A crutch structuraof the :oharacter stated Jill-018421154 wherein saidcmovementiimiting means for -the pistonecomprisesra bolt extending transversel-y through fthe-cylinder immediately :above ithe-col-lanand havlng its endshouseduin the lower endportiona of the ncrutch :stnucture, the piston :being; longitudinally slotted f or the extension of the boltltherethno l h.

MICHAEL SHELLHOUSE. CECIL E. CLEAVER.

REFERENCES CITED The following .refienences are of record: in #the die of this patent:

ITED "STATES PATENTS Number Name Date "923,352 Glasford June 1, 1909 1,183,008 Hipwood May 16, 1916 2,426,594 -Buel1et-a1 l Sept. 2,1947 

